ln() vs. log()

[jebem]

(04-18-2016 01:14 PM)Thomas Radtke Wrote:  My 35s returns zero for ln(1000)/ln(10)-3. Not too bad. But the same fails with 10,000 miserably (by 1*10^-11) ;-)

Got the same results (I think) with the HP 10bii+ and with the mighty HP Prime in Home mode:
\(\frac{LN(10000)} {LN(10)} -4 = 0.00000000001 \)

The HP Prime in CAS mode gives a much smaller difference result of just: \(-1.42108547152^{-14} \)

Although my humble Hp 300S+ and another Casio fx-991SPX manage to return zero for both cases.
To be fair, these two models only shows up to 10 mantissa digits, so they are not in the same league as the others.

However, taking the popular top class Texas ti-89 Titanium (at least in other forums...), with a setup to display 12 float digits in scientific format, it returns Zero for both cases.
Is this impressive?